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United States Patent | 5,564,010 |
Henry ,   et al. | October 8, 1996 |
A reset signal generator includes circuitry for detecting conditions indicating that a reset signal is necessary and generating a reset signal in response. Such conditions may include low power supply voltage (i.e., "brown out") or the presence of transient signal spikes. Circuitry is provided for extending the duration of the reset signal after power is initially applied, because at this time associated digital circuitry may not be fully powered-up, and may require a longer than normal reset pulse. In contrast, a reset pulse of a normal duration is generated when the digital circuitry is fully powered-up and a transient signal spike is detected. Isolating circuitry is coupled between the detecting circuit and the extending circuit to isolate the detecting circuit from the extending circuit when there is no power-on condition, (i.e. when normal operating voltage is present) in order to prevent the duration of the reset pulse from being extended.
Inventors: | Henry; Paul D. (Carmel, IN); Testin; William J. (Indianapolis, IN) |
Assignee: | Thomson Consumer Electronics, Inc. (Indianapolis, IN) |
Appl. No.: | 567711 |
Filed: | December 5, 1995 |
Current U.S. Class: | 714/22; 714/23 |
Intern'l Class: | G06F 011/00 |
Field of Search: | 395/182.2,182.21,750 364/273.4,948.9,948.4 |
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